DE 1 151 307 A discloses an oscillating armature drive for a dry shaving apparatus with a reciprocating shaving cutter. The oscillating armature drive has a U-shaped electromagnet formed with the housing of the shaving apparatus. A working armature and, on either side of the working armature, a compensating armature are arranged for oscillatory motion in the proximity of the poles of the electromagnet.
During operation, the working armature, which drives the shaving cutter, oscillates parallel to the pole faces of the electromagnet such that the compensating armature oscillates in phase opposition thereto in order to help prevent the oscillations of the working armature from being transferred to the housing of the shaving apparatus.
DE 196 80 506 T1 discloses an oscillatory linear motor having a stationary electromagnet and several movable components that are oscillated in phase opposition to each other by means of an electromagnet. To maintain the mutual phase relationship of the movable components under load, the components are interlinked by means of a linkage mechanism that transfers the oscillatory motion from one component to the other with simultaneous reversal of direction.
DE 197 81 664 C2 discloses an electric shaver with a linear drive that has a hollow cylindrical stator with an electromagnetic coil. Arranged in the stator are two movable elements that are driven in phase opposition to each other One of the elements drives a shaving cutter. The other element may have a counterweight to suppress vibrations.